Drawing apparatus



May 7, 1929. -w. E. ELAM DRAWING APPARATUS 2 Sheets-Sheet 1 Filed May '7, 1926 Q? WEEZam |NVE NTOR ATTORNEY WITNESS:

y 7, 1929- w. E. ELAM 1,712,106

DRAWI NG APPARATUS Filed May 7, 1926 2 Sheets-Sheet 2 anew-4 1 WEE'Za/m INVENTOR a\ ATTORNEY WITNESS:

Patented May 7, 1929.

UNITED STATES.

WILLIAM E. ELAINE, OF WASHINGTON, DISTRICT OF COLUMBIA.

DRAWING APPARATUS.

Application filed. May 7,

My present invention has reference to a drawing apparatus and has for its primary object a device of this character WlllOll Will, to a great extent, eliminate the employment of the ordinary rule, dividers, or other measuring instruments, required in the making of scaled straight line drawings, with the result that with my improvement drawings of this character may be more accurately executed in a more expeditiousmanner and with less strain on the mind and on the eyes of the draftsman.

This object. I attain by providing, two cooperating drafting plates; one a degree right angle triangle, and the other a 6()30 degree triangle.

In the accompanying drawings:

Figure 1 isa plan view of a 415 degree right a'ngletriangle in accordance with this invention.

Figure 2 is a similar View of a 60 3O degree triangle provided with the fingers and guards. I F'gure 3 is a view, in elevation, of one side of the triangle illustrated in Figure 1.

Figure 4 is a fragmentary plan view of both of the triangles in cooperating position Figure 5 is a fragmentary plan view to illustrate the adj u stable finger employed.

Figure 6 is an elevation of part of the triangle illustrated in Figure 2, showing the finger and the guards. I

Figure 7 is a plan view of a form of plate which may be employed.v I

On the upper or outer face of the triangle 10, in close proximity and parallel to the short sides 12 and 13 thereof, there are secured ribs 1 1, preferably of metal andrectangular in crosssection. These ribs are provided with upright transverse notches 16 that form graduations.

' Some of these notches are one inch apart to form one inchgraduations, and others are placed proper distances apart to. form fraction-of-an-inch graduations ofpredetermined lengths.

A like notched rib, similarlylplacedfis located along the side of the triangle" 11. p I

On the upper orouter face of the triangle 10 there are scribed parallel extension-lines registering with the walls of the notches, 16. These lines are numbered 0, 1, 2, 3, 4,5,6, v

,t ons provide theguards. ,7

and coincide with one of theperpendicular walls of each of the said notcheswhich are one inch apart, forming oneinch divisions 1926. Serial No. 107,453.

These numbered lines, are called base lines. Shorter similarlines, similarly located with respect to the notches that are less than one inch apart, form fraction-of-an-inch divisions of predetermined lengths. These short er lines, and the dimension lines 15 designate the fraction-of an-ineh 'graduation's For brevity the fraction-of-an-inch graduations are called minor graduations. For clearness some of the short dimension linesare not provided witharrow heads. 1

The oneinch divisions are successively con fraction 1/3 are,'theref0re, 1/3 of an inch graduations; and it is obvious that if finger 23 on trianglell be properly inserted in the notch at one end of a 1/3 inch graduation and a line properly scribed, then in the notch at the other end of it and a line scribed, the two lines will be 1/3 of an inch apart.

Graduations lessthan, equal to, or only slightly, longer than-the width'ofthe finger 23, are necessarily formed by means of one notch, the width of which is Just equal to the width of said finger'plusgthe length of the graduation. To illustrate, and referring to Figure 4, saythat the WLldthOf the finger is 1 16 of an'inc'h, then in case of a 1/16 graduation the distance from the finger to the confronting wall of the notch in which it is positioned, is just l/16' of an inch, and if the finger is made to contact with the' said wall, triangle 11 will have moved just 1/16 of an inch, as shown in Figure 4. The Width, therefore, of a notch forminga 1/16 inch graduation, is 1/8of an. inch. Obviously, the width of a'notch forming a '1/32 inch the notch.

p The finger 23 is formed on a'plate 22lthat I,

is rivetedor otherwise secured'fto the angle 11, the said plate 22 having at its corners projections 24 arranged parallel with but of a less width than the finger 23. These The extension lines, the arrow-headed dimension lines andthe figures accompanying the same, asscribed onplates 10, 11 and 35,

proj ecabove complementary manner,

form graduation charts 18. These charts can be printed upon suitable material and cemented to the plates.

As is well known, it an inch be divided into two parts, each part is a complement of the other, and it division is made as herein set forth, each can be used for laying oil a distance; and, furthermore, one end of each graduation will rest on a one inch base line. If one end of a graduation rests on a base line and there is another one-inch line properly located with respect to the one on which the graduation rests, said graduation plus an inch, can be laid off with but one shift ofthe' scribing plate as will be described further on.

It will be seen from an inspection of plate 10, Figure 1, that graduations formed in the equal in length to odd multiples of a graduation unit, can be located in one one-inch division, and those, equal in length to even multiples of c said unit, located in another. For example:

In the division between lines 34, the graduation unit is 1/16" and graduations consist ing of multiples thereof, placed therein, are equal in length to odd multiples, only, of l/lll. The graduations equal in length to the even multiples of 1/16, viz: 1/8, 1/4, 1/2, and 3/1 are formed in the division The complementary feature is not shown or availed of in making the 96ths and oaths graduations and their location is arbitrary.

The notches on one side 01'' the triangle 10, forming minor graduations, are arranged reversely with respect to the juncture of the perpendicular sides of the said triangle. For example, on side 12 ot the triangle 10, take notch 1/12; this forms a 1/ 12 inch graduation. It abuts on base line 0, while. notch 1 12 on side 13 of the triangle abuts on line 1', which is nearer the right angle of said triangle than is line 0. I

By reason of this feature there is always, on one side or the other or the two short sides of the triangle, a base line just one inch distant from the one on which a graduation or abuts and is so located with respect thereto that any graduation, plus an inch or inches caube laid 011' on the paper with but one shift of the scribing plate. For eXa nple, suppose the draftsman desires to lay oil 1 2/3 inches and then add 1 1/3 inches to it having found from an inspection of index similar to the one on triangle 11 and ot the graduations on triangle 10, that notches 1/6 1 and 11/96, and 10 S26 and 3/32 are, respectivclv. at the termini oi the desired 12/3 and 1 1/3 distances, he will insert finger'23 in notch 1/(34, side 12 of triangle 10 and sc-ribea line along the. long side of triangle 11, then, holding triangle 10 in place, insert finger 23 in notclr11/96 and inscribe a line, the two lines will be just 1 2/3 inches apart. Now holding triangle 11 in place, he will turn triangle 10 so that side'13 will take the place that side 12 occupied, and

above it.

Triangle 11 bears an index 33 containing a partial list of the graduations on chart 18. This index may be printed on suitable material and cemented to the upper faces of the triangles and consists of a block having four columns; in the first of which there are arranged consecutively figures denoting the 1/32 inch graduation and odd multiples thereof with their complementary graduations to the right. In the second column there are two columns oilt' figures. They correspond to those with which the base lines on chart '18 are numbered and they indicate, on triangles 10 and 11, the two lines between which a graduation is located. For example, the line of figures 1/3 31/32, 3 1, as arranged at top of columns 1 and 2, indicates that graduations 1 32 inch and 31/32 of an inch are located between the base lines 3 and 1 on the charts. The drai tsman, therefore, can tell by a glance at the index just where on the plate, a desired graduation is located, and is able to rapidly lay 011 on the paper any graduation, within the scope of the device, with but little or no more tax on the mind and on the eyes than is involved in the use of a section liner, and to make scaled drawings as he scribes the construction lines thereof, noprevious recourse to any rule, whatever, is necessary.

The base lines are consecutively numbered toward the intersection of the charts, hence, the one-inch division between the lines 5 and 6 common to both charts and bears graduations pertaining to each side of triangle 10. The plates 10 and 11 may be provided with adjustable fingers ontheir upper or outer faces arranged so that they will not project beyond the edges of the plates when not required tor use and whereby the said edges may be employed in scribing. The adjustable finger 26 on the plate 11 is carried by a. block 27 that is slidable in a housing 28. The block has on its rear end a threaded tension 29 that passes through the rear 01' the housing and the housing is slotted for the reception of a milled nut 30 that is screwed on the threaded part 29. This construction is also disclosed by dotted lines in Figure 1 and is indicated by the numeral 34.

i The plate 35, shown in Figure 7, is a rectangular parallelepiped. On it the minor gradnations are grouped as near to the center of the plate as practicable, and have one inch divisions between them and each end of the plate. By this arrangement more contacting surface is afi orded between two cooperating plates than is sometimes possibleit the graduation that is being used is located near one end of the plate. Furthermore fewer notches are required, hencecost of manufacture is less. Nevertheless with it, any otthe graduations expressed on plates and 11 can be laid oil with but two shifts of the scribing plate, and many of them with but one. The numeral. in Figures 1, 2 and 7 illustrates an anti-slipping device to prevent accidental movement oil the plates when they are being operated.

l-laving described the invention, 1 claim 1. A drafting device for the purpose set forth, comprising;- a guiding pla e having a notched rib on one face. adjacent and arallel to one of the edges of the plate, cut transversely to term notches abutting on extension lines connected by numeral bearin lines perpendicular to said extension lines and designating the length. of a graduation, and a second plate having an outstanding; linger adapted to operate in any of said notches.

2. A. dratting device comprising a right a np'led guiding plate havin notches one inch apart, along; two of its adjo-inin perpendicularsidcs, o 'z Ol'il'i divisions one inch in length, constituting one inch pgraduations and havll other notches intermediate ions less than one inch in lengtlii, conutinp; tractional inch graduations, said "fractional inch. graduations, on one side ot. the plate being; located in reverse order to those oit same size on the other side ot the plate and a second plate having a finger adapted to engage in any of the said notches when the corresponding: edges ot said plate are brought into contact.

8. In a drafting; device, a right angled guiding plate having, along two of its adjoining perpendicular sides, rectangula notches each having; one perpendicular wall coinciding with scribed lines on said plate one inch apart the lines on each side being numbered consecutively from the juncture of the said perpendicular sides, so that lines, on each side ot the j'ilate, equally distant from the said juncture, will bear the some numeral.

4%. A. drafting; device "for the purpose so forth, comprising a scribing plate having a notched rib on one face, parallel to one of the edges of the plate, a chart on said plate having graduation lines adjacent the notches connected by numeral bearing lines perpendicular to said graduation lines, and a second scribing; plate, a finger thereon adjustable to he projected. beyond the edge of theplate, and adapted to engage in any one of the notches of his plate edges are brought into contact,

A drafting device for the purpose set forth, comprising, a guiding plate having notches along one of its edges, forming; a plurality of: one-inch divisions, constituting, in connection with extension lines scribed on the plate one inch apart, one-inch graduations, and having, within the said one-inch these to term, within the said one inch divisions, di-

the rib when the correspond divisions, other notches and extension lines to form tractions-ot-an-inch graduations, a second plate having a finger adaptedto engage in any of the notches, and a guard for the linger. f

6. A drafting device for the purpose settorth, comprising a guiding plate having an upstanding rib on its upper face, adjacent and parallel to one of its edges, having transverse notches, one inch apart, with one wall of each coincident with an extension line, forming one-inch graduations, and, intermediate. the said notches, other notches, each having one wall coincident with an extension line connected by perpendicular numeral bearing lines, forming, in a complementary manner, fractions-of-an-inch graduations lo cated irregularly along; the edge of the said plate the entire length of its notch bearing portion, and a second platehaving a finger adapted to engage in any of the said. notches.

7. A dra'tting device for thepurpose set forth, cmnprising a guiding plate having,

along; one of its edges, notches, one inch apart, each having;- one wall coincident with extension lines. scribed on the plate, one inch apart, forming; a plurality of one-inch divisions, to form one-inch graduations, and, within the es 'd one-inch divisions, other notches having one wall. coincident with extension lines connected by 'ierpendicular numeral bearing lines, forming, in a complementary manner, .l lztct lfillS Oiii-iLU-iIICl} graduations, ct dilterent sizes, located irregularly along the edge o f the said plate the entirelength of its notchliearing portion, and a second plate having a finger adaptedto engage in any of the said notches.

8. draittsmmis guiding plate containing, along one of its edges, one-inch divisions termed by notches having a wall coincident with extension lines one inch apart, constitutinp; one-inch graduations, and, within the said, one-inch divisions, other notches and extension lines forming smaller graduations;

. said smaller graduations'equal 1n length to odd multiples of a graduation unit of. a predetermined size being; located in one one-inch division, and those, equal" in length to even multiples of the said unit being located in another of the said divisions. 9. A drawing apparatus comprising a right angled guiding; plate, graduated by notches, having at the juncture of two perpendicular sides, a division commonto both of said sides; said div sion containing notch termed fractions of an inch graduations designated by extension lines connected by 1ninneral-bearing; (lllllQllSlOl'l'llllQS scribed on the plate; and a cooperating plate provided with a linger adapted. to engagein any of the said notches.

la testimony whereof I a'fiixiny signature.

WILLIAM E; ELAM. 

